Filter



FIG. 1 is a front perspective view of a filter showing our new design;

FIG. 2 is a front elevational view thereof, the opposite side elevational view being a mirror image of that shown;

FIG. 3 is a side elevational view thereof, the opposite side elevational view being a mirror image of that shown;

FIG. 4 is a top plan view thereof; and,

FIG. 5 is a bottom plan view thereof. 

The ornamental design for a filter, as shown and described. 